1. Field of the Invention
This invention relates to a positioning mechanism. More particularly, the present invention relates to a structure for causing a number of jointed segments to curl together such as to simulate the swimming motion of an aquatic creature.
2. Description of Related Art
Small children who resist taking their baths can represent formidable foes for their parents. In order to help make bath time fun and enjoyable, and to provide general entertainment for children in the bathtub or the swimming pool, a number of toys have been introduced, including various powered swimming toys with the power being provided by windup springs, rubber bands, batteries, or the like. A number of mechanisms have been proposed for implementing mechanical fish tails, or other appendages of aquatic creatures such as mermaids, dolphins, and whales, for use in bath and swimming pool toys. Many of those mechanism rely on one or two flexible tendon-like rods or wires running down the length of the tail and offset from the center of a flexible or jointed mechanical frame, with the rods being pushed and/or pulled relative to the frame in order to induce a back and forth movement in the tail similar to the swimming motion of a real fish.
U.S. Pat. No. 6,773,327 issued to Felice et al. discloses such a mechanism. In Felice's structure, a rotating lever pulls on an elongated tendon-like device which extends down the length of a jointed and ribbed structure to cause that structure to curl. Structures that employ generally similar principles include U.S. Pat. No. 1,928,418 issued to Garland; U.S. Pat. No. 2,648,935 issued to Nagel; U.S. Pat. No. 5,297,443 issued to Wentz; U.S. Pat. No. 5,931,715 issued to Chang; and U.S. Pat. No. 6,458,010 issued to Yamagishi et al.